Method And Device For Monitoring Radioaltimetric Heights Of An Aircraft

• US 20110199253A1
• Filed: 02/04/2011
• Published: 08/18/2011
• Est. Priority Date: 02/15/2010
• Status: Active Grant

• Current Assignee: Airbus Operations (European Aeronautic Defence and Space Company EADS NV)
• Original Assignee: Airbus Operations (European Aeronautic Defence and Space Company EADS NV)
• Inventors: Houberdon, Nour-Ed-Din, Delga, Philippe
• Granted Patent: US 8,432,308 B2
• Time in Patent Office: Days
• US Class Current: 342/120
• CPC Class Codes: G01C 5/005 altimeters for aircraft G01C5/02, G01C5/06 take precedence
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• CPC Class Codes: G01S 13/882 for altimeters measuring height using barometric means G01C5/06
• CPC Class Codes: G01S 7/40 Means for monitoring or calibrating

Abstract

The device comprises means for generating an auxiliary height (HA) of an aircraft (AC) and for determining, with the aid of this auxiliary height (HA), an error in incoherent data which are received from two radioaltimeters.

Claims

1. A method for monitoring radioaltimetric heights of an aircraft (AC), wherein from two distinct radioaltimeters (2, 3), respectively, a first and a second radioaltimetric height are received relative to a same position of the aircraft (AC), wherein:

a) an auxiliary height (HA) is determined, using an on-board auxiliary source (4) being dissimilar and independent from said radioaltimeters (2, 3), said auxiliary height (HA) being relative to the same position of the aircraft (AC) as said first and second radioaltimetric heights, and for determining said auxiliary height (HA), the following operations are carried out;

the current altitude of the aircraft (AC) is determined from measurements carried out by on-board means;

data base of the field being flown over is taken into consideration, containing a decomposition of said field into a plurality of adjacent cells, each of which being associated with a corresponding altitude; and

said auxiliary height (HA) is calculated, subtracting at the thus determined current altitude, the altitude of a cell originating from said data base, being representative of the current lateral position of the aircraft (AC);

b) the coherence between said first and second radioaltimetric heights is checked; and

c) should an incoherence occur between this first and this second radioaltimetric heights, using said auxiliary height (HA), the most reliable amongst said first and second radioaltimetric heights is determined; and

d) the following operations are performed;

should a coherence occur between the first and the second radioaltimetric heights, said first and second radioaltimetric heights are transmitted to at least one user device; and

should an incoherence occur between the first and the second radioaltimetric heights, the most reliable radioaltimetric height is transmitted to at least one user device and the other radioaltimetric height is considered as erroneous.

2. The process according to claim 1,

characterized in that in step b):

the difference is calculated between said first and second radioaltimetric heights;

said difference is compared with a first threshold value; and

it is considered that these first and second radioaltimetric heights are coherent if said difference is lower than said first threshold value for a period of confirmation;

otherwise, it is considered that said first and second radioaltimetric heights are incoherent.

3. The process according to claim 1,

characterized in that in step c):

c1) a first difference is calculated corresponding to the absolute value of the difference between one of said radioaltimetric heights and said auxiliary height (HA);

c2) a second difference is calculated corresponding to the absolute value of the difference between the other one of said radioaltimetric heights and said auxiliary height (HA);

c3) these first and second differences are compared therebetween; and

c4) it is considered that the radioaltimetric height, for which the difference is the lowest, represents the most reliable radioaltimetric height.

4. The process according to claim 3,

characterized in that in step c), in addition, the lowest difference is compared with a second threshold value, and in that, in step d), the two radioaltimetric heights are transmitted to a user device, if this lowest difference is higher than said second threshold value.

5. The process according to claim 1,

characterized in that the steps of said method are implemented repeatedly, using the first and the second radioaltimetric height received repeatedly from said radioaltimeters (2, 3).

6. A device for monitoring radioaltimetric heights of an aircraft (AC), said device (1) receiving from two distinct radioaltimeters (2, 3) a first and a second radioaltimetric heights relative to a same position of the aircraft (AC), said device (1) comprising:

means (4) for determining an auxiliary height (HA), using an auxiliary source being dissimilar and independent from said radioaltimeters (2, 3), said auxiliary height (HA) being relative to the same position of the aircraft (AC) as said first and second radioaltimetric heights, said means (4) comprising elements for respectively;

determining the current altitude of the aircraft (AC) from measurements carried out by on-board means;

taking into consideration a data base of the field being flown over, containing a decomposition of said field into a plurality of adjacent cells, each of which being associated with a corresponding altitude; and

calculating said auxiliary height (HA), subtracting at the current altitude, the altitude of a cell originating from said data base, being representative of the usual lateral position of the aircraft (AC);

means (5) for monitoring the coherence between said first and second radioaltimetric heights; and

means (8) for determining, should an incoherence occur between these first and second radioaltimetric heights, using said auxiliary height (HA), which one of said first and second radioaltimetric heights is the most reliable, and for transmitting;

should a coherence occur between the first and the second radioaltimetric heights, said first and second radioaltimetric heights to at least one user device; and

should an incoherence occur between the first and the second radioaltimetric heights, the most reliable radioaltimetric height at least one user device, the other radioaltimetric height is considered as erroneous.

7. An aircraft system of the type receiving from two distinct radioaltimeters (2, 3), respectively, a first and a second radioaltimetric heights relative to a same position of the aircraft (AC),

characterized in that it comprises a device (1) such as specified in claim 6.

8. An aircraft,

characterized in that it comprises a device (1) such as specified in claim 6.